DNA exonerations of innocent individuals have consistently implicated eyewitness misidentification as a leading cause of wrongful conviction. A key factor producing these eyewitness misidentifications is social influence, or the process by which interactions with a police investigator affect eyewitnesses’ identification decisions. In an attempt to reduce social influences in eyewitness identification, researchers have recommended the implementation of double-blind lineup procedures in which the lineup administrator does not know which lineup member is under suspicion. However, even double-blind lineup administrators sometimes engage in behaviors that could influence eyewitness decision-making. This project will test whether double-blind lineups are sufficient to prevent social influence from increasing mistaken eyewitness identifications. The findings could support the development of more effective policy reforms by demonstrating a need to move toward fully computerized administration of eyewitness identification procedures, a practice that has yet to be adopted by law enforcement agencies in the United States.
This project consists of a series of experiments that will examine social-influence processes in double-blind lineups. First, these experiments will identify social-influence behaviors emitted by double-blind administrators and assess their effects on eyewitness decision-making. Second, the experiments will test whether administrator influence in double-blind lineups can increase the risk of eyewitness misidentification of innocent suspects by exacerbating the effects of lineup factors that bias witnesses towards identifying the suspect (e.g., unfair lineups, repeated exposure to the suspect). Third, the experiments will examine how social-influence effects carry over across multiple identification procedures and assess whether some eyewitnesses are more vulnerable to social influence effects than others. Fourth, the experiments will test competing psychological theories regarding whether social influence has stronger effects on identifications of guilty or innocent suspects. Finally, the experiments will assess the effects of administrator influence on the diagnostic value of eyewitness confidence, which is relied upon by fact-finders (e.g., judges and jurors) to assess the reliability of eyewitness identification evidence.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
